Had the same problem myself. Dell changed printer but problem still the same. In the end the solution was to set the answer to ONE ring only. Didn't solve the problem entirely but went from about 6 people not being able to fax to just 1 not being able to and that could have been a compatabilty problem.

 

Regards

Roy

Thank you very much for your reply Roy. Can you please tell me where can I set the answer to one ring?

Try the procedure below.

Also - here is the link to the manual    http://support.euro.dell.com/support/edocs/systems/prn3115c/en/index.htm

   Specifying the Fax Settings Changing the Fax Settings Options

1. Press until >SETUP appears, and then press .
   
   
2. Press until >Admin Menu appears, and then press .
   
   
3. Press until >Fax Settings appears, and then press .
   
   
4. Press until the desired menu item appears, and then press .
   
   
5. Use to find the status or use the number keypad to enter the value for the option you have selected.
   
   
6. Press to save the selection.
   
   
7. Press Back to return to the previous screen.
   
   
8. If necessary, repeat steps 4 through 7.
   
   
9. To return to the standby mode, press Cancel.
   

I found the menu but the answer fax settings are in seconds, not in no of rings. Thanks.

Forgot that it is in seconds - Try 1 the 0

Thanks Roy, I'm waiting for some faxes to see if that does it :D